中文摘要：

钨基合金喂料在挤压过程中具有坯料非连续性、力学性能不确定的特点，采用金属类屈服准则来表征钨基合金喂料强度已不适应。采用线性Drucker-Prager准则（D-P准则），通过变角剪切试验测定钨基合金喂料的摩擦角和粘聚力，在MSC.Marc中实现了对钨基合金喂料正挤压的有限元模拟。结果表明：采用线性D-P准则能更好地描述挤压过程中喂料的强度变化及受力过程；基本挤压阶段实际挤压力为137 kN，与通过模拟积分得到挤压力146 kN的相对误差为6.5%，说明所建立模型对钨基合金喂料增塑挤压成形具有较好的适应性。

英文摘要：

It is not accurate to characterize the feed intensity of the tungsten-based alloys using the metal yield criterion, due to the discontinuity of feed and the uncertainty of mechanical properties during the process of extrusion. Based on the linear Drucker-Prager criterion,the extrusion process of the tungsten-based alloys feed was simulated utilizing the finite element analysis software of MSC.Marc. The friction angle and cohesion of the feed were measured by the variable angle shearing test. The results show that the change of the feed intensity and the force during extrusion can be described more specific by applying the linear D-P criterion. The actual extruding force is 137 kN, whereas the simulating extruding force is 146 kN. The relative error is only 6.5%,indicating that the mold based on the D-P criterion is adapted well to the feed extrusion of the tungsten-based alloys.